Pepo Squash

This article is for the many varieties of the species Cucurbita pepo, including zucchini, spaghetti squash, summer squash, and acorn squash. Since they are capable of cross pollinating, you should separate varieties of this species by at least 500 feet if you plan to collect seed. It is possible to reduce cross-breeding by hand pollinating. See the section on pollination.

Germination
Sow in full sun, 1" deep. Seeds will germinate best in soil which is 70° F. Allow 10 days for germination. Thin to 18-30" apart. Squash plants can quickly become root bound. If starting indoors, transplant as soon as true leaves develop.

Pollination
Squash is cross-pollinated by bees.

To hand pollinate: Inspect your flowers in the early evening. If any look like they will open the following morning, use masking tape to secure the tips shut. In the morning after any dew has dried, identify the sex of your taped flowers. The females will appear to have a tiny squash at the base, while the males will simply have a straight stem. Select a male flower and cut it loose. Remove the tape and all petals. Select a female flower (preferably on a different plant) and tear off the tape and flower tip. The female flower will open. Using  your prepared male flower, apply pollen to the stigma of the female flower. Immediately re-tape the female flower closed and mark the stem.

Seed Collection
       As summer squash is typically harvested immature, without fully developed seeds, you will need to allow some to grow much longer than usual. Cut your fully matured squash open and remove the seeds and pulp with a spoon. Wash gently by placing in a bowl of water and working with your fingers until the seeds separate. Spread out on paper or screens to dry for up to a week, rearranging them daily to make sure they do not rot.